1. Field of the Invention
This invention relates to a method to selectively mitigate intergranular stress corrosion cracking (IGSCC) by rapid quench melting through the use of a pulsed laser. Such methods of the type, generally, mitigate reactor pipe cracking by rapidly melting the sensitized material to redissolve chromium carbide and then rapidly cooling the sensitized material such that corrosion cracking can be avoided.
2. Description of the Related Art
It is known, that during operation of boiling water reactors (B.W.R.) that steam bypass lines may develop intergranular stress corrosion cracking (IGSCC). The IGSCC can adversely affect the structural integrity of the steam bypass lines and cause the boiling water reactor to be shut down. Three elements are critical to the formation of IGSCC. They are:
(1) Residual Stress PA0 (2) Sensitization PA0 (3) Reactor Chemistry.
Reactor chemistry is generally fixed so that there are only two viable solutions to the IGSCC problem. Of these, although they can be reduced by optimized welding procedures, residual tensile stresses in the weld near field are unavoidable. Consequently, there is extreme need for a suitable method to mitigate the interdiameter surface of reactor pipes where IGSCC starts. Therefore, a reduction in the amount of IGSCC is critical.
It is apparent from the above that there exists a need in the art for an IGSCC mitigation method which is capable of mitigating cracks which form in reactor pipes and other reactor components. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.